The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Despite the widespread use of computers and information technology, some areas of commerce continue to require archaic practices, such as requirements for physical signatures. In response, some organizations, such as the United States Patent & Trademark Office, have relaxed their requirements for handwritten signatures and will accept electronic signatures comprised of typewritten (ASCII) characters. Similarly, electronic commerce is widely performed without use of handwritten signatures or other handwritten information. The Federal Rules of Evidence treat electronic signatures and handwritten signatures equivalently. Nevertheless, a physical signature remains required practice in many commercial fields. For example, real estate transactions are often documented by multiple facsimile transmissions containing handwritten signatures and text, even though legibility may be difficult and there is no convenient way to digitally store signature information.
However, in some cases handwriting and physical signatures are desirable. For example, collaborative document editing and management is sometimes better performed using handwriting rather than a keyboard.
Marking and annotating documents on a computer screen has been difficult or expensive in past practice. Digitizing tablets have been used to enable sketching on computer screens. Typically such digitizing tablets have used sophisticated pressure sensing circuits and materials, but they are not easy for ordinary people to use. Further, relatively few digitizing tablets are deployed in the field and few host computer applications (such as personal computer applications) can accept input from digitizing tablets. One manufacturer offers displays with integrated pen sensors, but these displays are very expensive and not easy to carry. Tablet computers have been offered, but for reasons of price and functionality, have not proved popular.